Stamped dual snowmobile runner and method of manufacture

ABSTRACT

A runner and method of making a runner for mounting on a snow ski including a runner body fabricated of one piece of stamped metal which includes a central base portion and a pair of longitudinally extending runner portions which are bent downwardly from the base portions in laterally spaced relationship to one another. Carbide wear strips are secured to the lower edges of the runner portions, while the base portion  18  is fitted with mounting structure  48  which extends upwardly from the base portion and does not extend into the channel  36 . The mounting structure  48  may be formed as one piece with the runner body  16  of the same material, has one or more tab features, and may be threaded and/or pierced to accommodate an associated net or mounting pin as desired for mounting the runner.

This application claims priority from U.S. Utility application Ser. No.11/027,448 filed Jan. 3, 2005 and U.S. Utility application Ser. No.12/283,202 filed Sep. 10, 2008.

BACKGROUND OF THE INVENTION

This invention relates generally to replaceable runners for snowmobileskis, and to methods of making such runners, and more particularly torunners having dual running edges.

RELATED ART

It is common in the field of performance snowmobiling to outfit the skisof the snowmobile with wear bars or runners in order to improve thesteering traction and wear of the ski and thus handling of thesnowmobile. The typical traction bar used in performance racing ofsnowmobiles is constructed from a length of steel rod that serves as thebody of the traction bar. A pair of threaded studs are welded to the topor non-terrain contacting side of the bar and are received in associatedmounting holes provided in the skis to enable the wear bar to beremovably mounted on the skis by corresponding fastener nuts. Anopposite lower terrain contacting side of the wear bar is typicallyformed to include a channel in which a wear strip of carbide material ismetallurgically bonded to present a, wear-resistant traction stripextending lengthwise of the ski, and acting to bite into the terrain toprovide enhanced traction and steerability, particularly on icy terrain.

One draw back to the use of such wear bars is the weight which they addto the snow machine. Additionally, there is relatively high costinvolved in the prior art manufacturing process which is labor intensivein that the mounting studs need to be welded to the bar and a slotmachined in the lower terrain contacting surface of the bar to receivethe carbide wear strip.

Traction-enhancing wear bars are also beneficial to recreationalsnowmobilers. In the non-performance category, the configuration of thewear strips is less restrictive than that for competitive racing. Forexample, recreational traction bars can include dual runners so thateach ski includes a pair of spaced, longitudinally extending tractionstrips instead of just one per ski. There are several examples of dualrunner traction systems in the snowmobile art including U.S. Pat. No.3,718,341 which shows a generally U-shaped saddle piece used inconjunction with a conventional wear bar to enhance traction; U.S. Pat.No. 3,844,367 which, again, shows a generally U-shaped dual runnertraction plate used in conjunction with a conventional wear bar; and U.Spublished application no. 2003/0024751 which shows an H-shaped dualrunner traction bar fabricated by welding a set of side plates to acentral mounting plate and then drilling a series of holes in thecentral mounting plate to receive fasteners extended upwardly from alower underside channel of the wear bar into support structure of theski. The multi-panel fabrication technique is costly and adds additionalsteps to the manufacture of such runners.

A runner constructed according to the present invention overcomes orgreatly minimizes the deficiencies of the foregoing prior artstructures.

SUMMARY OF THE INVENTION

A runner constructed according to a presently preferred embodiment ofthe invention includes a runner body fabricated of one piece stampedmetal having a central base portion extending longitudinally betweenopposite and longitudinal ends and laterally between opposite sides, andincluding a pair of longitudinally extending runner portions providedalong the laterally opposite sides and fabricated of the same one-piecestamped metal as that of the base portion and fixed to the base portionby intervening bent portions of the runner body such that the runnerportions project downwardly and terminate at lower free edges and definea generally U-shaped channel on the underside of the runner body. Therunner further includes mounting structure secured to the runner body inspaced relation to the U-shaped channel operative to mount the runnerbody on the underside of the snowmobile ski. The invention also providesa method for forming such a runner in which the mounting structure iskept free of the U-shaped channel of the one-piece runner body.

The invention has the advantage of maintaining the underside openchannel of the one-piece runner body free of any mounting structurewhich could otherwise serve to entrap rocks and other debris within thechannel or damage the mounting hardware, thereby impairing theperformance of the dual runner system.

A further advantage of the present invention is a one-piece wear bar andmount which is lightweight, structurally sound, and relativelyinexpensive to manufacture.

The invention has the further advantage of simplifying the manufactureof such runners by eliminating the need to extend the mounting structureinto the open shaped channel of a one-piece U-shaped runner body.

According to a further aspect of the invention, carbide wear strips maybe joined to lower free edges of the runner portions, and the carbidewear strips may further be staggered in the longitudinal direction ofthe runner body so as to further prevent rocks and debris from becomingentrapped within the runner channel on account of the wear strips, asmight occur if the wear strips were arranged opposite one another acrossthe channel.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention willbecome more readily appreciated when considered in connection with thefollowing detailed description and appended drawings, wherein:

FIG. 1 is a sectional side elevation view of a runner shown mounted on aski, taken along the section line 1-1 of FIG. 3;

FIG. 2 is a plan view of the runner of FIG. 1 in a stage of manufacture;

FIG. 3 is an enlarged sectional view taken generally along lines 3-3 ofFIG. 1;

FIG. 4 is a slightly enlarged fragmentary perspective view of the runnerof FIG. 2 shown in a stage of manufacture later than that illustrated inFIG. 2;

FIG. 5 is a slightly enlarged plan view of a sheet of flat plate stockmaterial from which the one piece runner is stamped along the shape ofthe workpiece outlined in phantom lines;

FIG. 6 is an end elevational view, taken along lines 6-6 of FIG. 5;

FIG. 7 is a plan view of a shaped workpiece or runner blank cut from theplate stock of FIG. 5;

FIG. 8 is a view similar to FIG. 7 but illustrating carbide wear stripsjoined to the blank prior to bending the blank to the U-shapedconfiguration;

FIG. 9 is a plan view of an alternative embodiment of a slightlymodified runner illustrated in FIG. 10 following bending but prior toinstallation of the mounting fasteners;

FIG. 10 is a side elevation view of the runner of FIG. 9 with threadedfasteners shown joined to the top side of the runner body;

FIG. 11 is an enlarged cross-sectional view taken along section line11-11 of FIG. 10;

FIG. 12 is an enlarged cross-sectional view taken along line 12-12 ofFIG. 10 illustrating the carbide wear rails metallurgically bonded tothe notches in the bottom edges of the runner portions;

FIG. 13 is a side elevation view of a second alternative embodiment ofanother slightly modified runner according to the invention; and

FIG. 14 is a bottom view of the runner of FIG. 13 in the direction oflines 14-14 illustrating the staggered arrangement of the wear strips.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A traction increasing runner 10 made according to a first presentlypreferred embodiment of the invention is shown generally at 10 in FIG.1-8, and is illustrated in FIGS. 1 and 3 as being mountable to anunderside 12 of a snowmobile ski 14, as it would be mounted in use.

The runner 10 includes a runner body 16 having a central base portion 18extending between opposite longitudinal ends 20 and 22, respectively,and a pair of longitudinally extending, laterally spaced runner portions24, 26 provided along laterally opposite sides 28, 30, respectively, ofthe base portion 18. The base portion 18 includes a rearward baseportion 25 having a predetermined width 27 and a forwardly projectingnose 29 of a substantially lesser width and which is upwardly bent at 31to be received in a forward aperture 33 provided in the ski 14.According to the invention, the base portion 18 and runner portions 24,26 are fabricated from a single, one-piece stamped metal piece, suchthat the runner portions 24, 26 are joined to the opposite sides 28, 30of the base portion 18 by intervening bent portions 32, 34. As shownbest in FIGS. 3 and 4, the runner portions 24, 26 extend transverselydownwardly from the base portion 18, providing the runner body 16 with agenerally U-shaped cross-sectional profile, defining an open U-shapedchannel 36 on an underside 38 of the runner body 16. The runner portions24, 26 terminate at lower free edges 40, 42 to which wear-resistantcarbide wear strips 44, 46 are attached along at least a portion of thelength of the free edges 40, 42 as will be explained in greater detailbelow.

The runner body 16 is provided with mounting structure 48 that extendsupwardly from the base portion 18 and is operative to mount the runner10 to the underside 12 of the ski 14. According to the first embodiment,the mounting structure 48 is fabricated of one piece with the runnerbody 16 out of the same material. As shown best in FIGS. 2 and 4, themounting structure 48 according to this first embodiment may comprisebent tab portions 50 which are fabricated of the same one piece materialas that of the runner body 16 and which are cut out of the base portion18 and then bent upwardly from an upper surface 52 of the base portion18 so as to project in a direction opposite the runner portions 24, 26.As shown best in FIGS. 2 and 4, the tab portions 50 may be made byconcurrently stamping a U-shaped cut 54 through the base portion at thelocations of the tab portions or regions 50 to isolate the materialwithin the U-shaped cut 54 while remaining attached at a base end 56 ofthe tab portions 50 so as to remain one piece with the runner body 16.

The tab portions or regions 50 are preferably rectangular and may havelaterally outer edges 51 and 53 formed with screw threads 58 in order toaccommodate a fastener nut 60 when inserted through apertures 59provided in the ski 14, as in FIG. 1. Alternatively, or in addition tothe screw threads 58, the tab portions 50 may be formed with a hole oropening 64 or other feature to receive a pin or wedge for mounting therunner 10 on the ski 14. FIG. 1 illustrates one of the tab portions 50fitted with such a pin or wedge 62 passing through the hole or opening64 to pin or wedge the runner 10 to the underside 12 of the ski 14,either in lieu of or in cooperation with the nuts 60 of other tabportions 50. The invention contemplates that the tab portions 50 can beeither threaded, provided with the pin opening 64, or both to providethe user with different mounting options. In both instances, the tabportions 50 are nonetheless formed as one piece with the runner body 16out of the same material as that of the runner body 16. Also, theinvention contemplates that while the tab portions 50 project generallyupwardly from the runner body 16 away from the runner portions 24, 26,the tab portions 50 may not be necessarily perpendicular to the uppersurface 52 of the base portion 18, but could be arranged at an angle orhave some shape other than that of the straight up configuration shownin FIG. 1. In any regard, the mounting structure 48 does not extend intothe open channel 36 and in this way keeps the channel 36 free from anyobstruction by the mounting structure 48, so as not to entrap rocks andother debris that may enter the channel and otherwise become caught onthe mounting structure if it were to extend into the channel 36.

The Method of Fabricating

The manufacture of the runner body 16 begins with a flat sheet 66 ofstock material. The stock material may be fabricated of steel, such as alow carbon plain steel like SAE 1018, or could be manufactured frommedium (SAE 1045) or high carbon (SAE 1090) steels or spring grade orstainless steel alloys, to name a few, as well as from non-ferrousmaterials such as aluminum or its alloys.

The flat stock planar material 66 is stamped or cut with a stampingmachine having a cutting die with an outline conforming to the outlineof the workpiece W to provide the general outline of the interimworkpiece W which is subsequently bent to form the runner body 16. Thelateral side edges 69 of the workpiece W are cut to include rearward,rearwardly converging edge portions 71 and forward, forwardly convergingedge portions 73 which project forwardly to form an integral forwardnose or tongue 29 have a substantially reduced width. A plurality ofU-shaped cuts 54 may be concurrently stamp cut with the stamp cutting ofthe workpiece W from the planar sheet 66. Notches 68 may besimultaneously stamp cut in the edges 69 of the stock material 66, asillustrated in FIGS. 5 and 7 in order to provide a location for mountinga strip 44, 46 of hard material, such as carbide, having a hardnesssubstantially greater than the hardness of the metal stock material 66.The carbide wear strips 44, 46, as illustrated in FIG. 8, may bemetallurgically secured or bonded by brazing or welding to the stockmaterial 66 while still in sheet form and prior to bending the lateraledges of the downward sheet in opposite direction to form the bentrunner portions 24, 26. The invention also contemplates that the carbidestrips 44, 46 could be added after the runner portions 24, 26 are bentto the positions illustrated in FIGS. 3 and 4, if so desired. After thecarbide wear strips 70 are metallurgically secured to the runners 24,26, the assembly is quenched in a quenching medium, such as oil, at apredetermined and controlled quench rate to generate a predeterminedgreater hardness of the workpiece material of between 45 to 65 RC toimprove the wearability of the runners 24, 26. The 45 to 65 RC hardnessis substantially greater than the initial hardness of the sheet 66 priorto hardening but still substantially less than the yet greater hardnessof the carbide wear strips 70. The tabs 50 can be bent upwardly frompositions lying in the plane of the base portion 18 to operative,upstanding positions illustrated in FIGS. 1 and 4 before, after orconcurrently with the downwardly bending of the legs 24, 26 in oppositedirections relative to the base portion 18 but preferably prior to thequenching. The threads 58 can be concurrently stamp cut in the laterallyouter edges 51, 53 of tabs 50 when the workpiece W is stamp cut or theycan be cut therein after the tabs are swung to the upstanding positionsillustrated in FIGS. 1 and 4.

The laterally opposite runner portions 24, 26 are then bent or foldedabout fold lines X and Y, respectively, in opposite directions frompositions in the plane of the base portion 18 to depending, confrontingpositions illustrated in FIG. 4 to form the channel 36. The bentportions 32 and 34 are located along the fold lines X and Y. The nose 29is upwardly bent from a position in the plane of the rear base portion25 to the upturned position illustrated in FIG. 1 and thereafter,inserted into the front ski aperture 33. The upstanding tab portions 50are also inserted through the ski aperture 59 so as to project above theupper surface 61 of the ski 14. If the tab portions 50 are threaded,nuts 60 are turned thereon to upwardly force the upper surface 52 of therunner body 16 against the underside 12 of the ski 14. If the tabportions 50 include the hole 64, wedges 62 are inserted in the holes 64to upwardly wedge the runner 16 against the underside 12 of the ski 14to minimize snagging of the runner 16 on the terrain.

FIG. 3 illustrates a preferred construction of the carbide wear strips70, in which the strips 44, 46 are no wider than that of the stockmaterial and are relatively shorter in length than the runner portions24, 26, as illustrated in FIG. 10. The wear strips 70 are preferablyjoined to the lower edges of the runner portions 24, 26 in the mannerdescribed above.

Alternate Embodiment

FIGS. 9-12 illustrate an alternate embodiment of a slightly modifiedrunner wherein the same reference numerals are used to designate likefeatures but are offset by 100.

FIG. 9 shows a top view of the stock material 166 following bending ofthe runner portions 124, 126 relative to the base portion 118. It isnoted that the tab portions described previously are omitted in favor ofthreaded studs 72, shown in FIGS. 10-12, which can be welded to the topsurface 152 of the base portion 118 at the appropriate locations toenable the runner body 16 to be mounted on the ski. As with the tabportions 50, the threaded studs 72 do not project into the channel 136and thus maintain the channel 136 free of any of the mounting structure148.

FIG. 12 illustrates the construction of the carbide wear strips 170, inwhich the strips 144, 146 are no wider than that of the stock materialand are relatively shorter in length than the runners 144, 146, asillustrated in FIG. 10. The wear strips 170 are preferably joined to thelower free edges of the runner portions 124, 126 in the manner describedabove.

Second Alternate Embodiment

FIGS. 13 and 14 illustrate a second alternative embodiment of a slightlymodified runner, wherein the same reference numerals are used todesignate like features, but are offset by 200. The runner 210 of FIGS.13 and 14 includes the one-piece runner body 216 including the baseportions 218 and bent runner portions 224, 226. The runner portions 224,226 are fitted with carbide wear strips 244, 246 which, as illustrated,are longitudinally staggered. As shown in FIG. 14, this staggeredrelationship is one in which the wear strip 244 on one of the runnerportions 224 is laterally misaligned with the wear strip 246 on theopposite runner portion 226. This staggered relationship of the wearstrips 244, 246 enables any rocks and debris that may enter the channel236 to more easily pass by the carbide wear strips 244, 246 withoutbecoming caught or entrapped between the wear strips. For example, arock entering the channel 236 is able to encounter only one of the wearstrips 244, 246 at a time and thus cannot become trapped between themdue to their offset relationship.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described. The inventionis defined by the claims.

1. A traction increasing runner for mounting on the underside of asnowmobile ski, comprising: a runner body fabricated of one piecestamped metal having a predetermined hardness, a central base portionhaving upper and lower faces and extending longitudinally betweenopposite longitudinal ends and laterally between opposite sides, andincluding a pair of longitudinally extending runner portions providedalong said laterally opposite sides of said base portion and fabricatedof the same one-piece stamped metal as that of the base portion andfixed to said base portion by intervening bent portions of said runnerbody such that said runner portions project transversely downwardly ofsaid base portion and terminate at lower free edges thereof and defininga generally U-shaped channel on an underside of said runner body; andmounting structure, secured to said runner body in spaced relation tosaid U-shaped channel, operative to mount said runner body on theunderside of the snowmobile ski.
 2. A traction increasing runner formounting on the underside of a snowmobile ski, comprising: a runner bodyfabricated of one piece stamped metal having a predetermined hardness, acentral base portion having upper and lower faces and extendinglongitudinally between opposite longitudinal ends and laterally betweenopposite sides, and including a pair of longitudinally extending runnerportions provided along said laterally opposite sides of said baseportion and fabricated of the same one-piece stamped metal as that ofthe base portion and fixed to said base portion by intervening bentportions of said runner body such that said runner portions projecttransversely downwardly of said base portion and terminate at lower freeedges thereof and defining a generally U-shaped channel on an undersideof said runner body; and a mounting structure, secured to said runnerbody in spaced relation to said U-shaped channel, operative to mountsaid runner body on the underside of the snowmobile ski; said mountingstructure being formed as one piece with said runner body.
 3. A tractionincreasing runner for mounting on the underside of a snowmobile ski,comprising: a runner body fabricated of one piece stamped metal having apredetermined hardness, a central base portion having upper and lowerfaces and extending longitudinally between opposite longitudinal endsand laterally between opposite sides, and including a pair oflongitudinally extending runner portions provided along said laterallyopposite sides of said base portion and fabricated of the same one-piecestamped metal as that of the base portion and fixed to said base portionby intervening bent portions of said runner body such that said runnerportions project transversely downwardly of said base portion andterminate at lower free edges thereof and defining a generally U-shapedchannel on an underside of said runner body; and mounting structure,secured to said runner body in spaced relation to said U-shaped channel,operative to mount said runner body on the underside of the snowmobileski—said mounting structure comprising at least one mounting tabfabricated of the same one piece stamped metal as that of the runnerbody projecting from said upper face of said base portion in a directionaway from said runner portions.
 4. The runner of claim 3 wherein said atleast one mounting tab is spaced from said longitudinally opposite endsof said base portion.
 5. The runner of claim 3 wherein said base portionincludes a cut-out region separating edge portions of said at least onemounting tab from said base, and wherein said mounting tab extendsupwardly away from said cut-out region and is joined to the base portionby a bent base end of said at least one mounting tab.
 6. The runner ofclaim 5 wherein there are a plurality of said mounting tabs.
 7. Therunner of claim 3 wherein said at least one mounting tab includes screwthreads.
 8. The runner of claim 3 wherein said at least one mounting tabis formed with an opening adjacent a free end thereof for receiving afastener.
 9. (canceled)
 10. A traction increasing runner for mounting onthe underside of a snowmobile ski, comprising: a runner body fabricatedof one piece stamped metal having a predetermined hardness, a centralbase portion having upper and lower faces and extending longitudinallybetween opposite longitudinal ends and laterally between opposite sides,and including a pair of longitudinally extending runner portionsprovided along said laterally opposite sides of said base portion andfabricated of the same one-piece stamped metal as that of the baseportion and fixed to said base portion by intervening bent portions ofsaid runner body such that said runner portions project transverselydownwardly of said base portion and terminate at lower free edgesthereof and defining a generally U-shaped channel on an underside ofsaid runner body; and a mounting structure, secured to said runner bodyin spaced relation to said U-shaped channel, operative to mount saidrunner body on the underside of the snowmobile ski; said lower freeedges of said runner portions being formed with a notch recessed intosaid runner portions from said lower free edges, and said wear stripscomprising carbide wear bars disposed in said notches, said carbide wearbars being the same width as the lower free edges of the runnerportions.
 11. The runner of claim 3 wherein said mounting tabs and saidbase portion have the same thickness. 12.-17. (canceled)
 18. A method offabricating a runner for mounting on the underside of a snowmobile ski,comprising: preparing a single generally planer sheet of metal materialhaving a predetermined hardness, a generally uniform thickness and upperand lower faces; separating a shaped workpiece from the planer sheet;bending predetermined runner portion side regions of the shapedworkpiece out of the plane of the workpiece to extend the runnerportions downwardly from laterally opposite sides of a centrallongitudinally extending base portion of the workpiece and defining agenerally U-shaped channel on an underside of the workpiece; and formingmounting portions on the base portion that project upwardly from a topside surface of the base portion and which do not extend into saidU-shaped channel.
 19. (canceled)
 20. The method of claim 19 includingsecuring a hardened wear strip having a hardness greater than saidpredetermined hardness of said metal material in each of the notches.21. The method of claim 19 wherein the notches are formed prior tobending the runner portions.
 22. The method of claim 21 wherein thenotches are formed during the separation of the workpiece from thesheet.
 23. The method of claim 19 wherein said hardened wear strips aresecured to the runner portions following the bending of the runnerportions.
 24. The method of claim 19 wherein said hardened strips aresecured to the runner portions before the runner portions are bent. 25.The method of claim 19 wherein said hardened wear strips comprisecarbide wear strips secured with a metallic bond by heating saidworkpiece and said carbide strips to an elevated bonding temperature,after which the united workpiece and carbide strips are quenched at acontrolled rate to generate a hardness of the workpiece material ofbetween about 45 to 65 Rc.
 26. The method of claim 25 wherein theworkpiece is fabricated of SAE 1045 plain carbon steel.
 27. The methodof claim 18 including forming the mounting portions by isolating amounting tab region of the base portion and then bending the mountingtab region upwardly out of the general plane of the base portion. 28.The method of claim 27 including forming a plurality of the mounting tabregions.
 29. The method of claim 28 including forming thread regions onthe tab regions.
 30. The method of claim 27 including forming a hole ineach of the mounting tab regions.
 31. The method of claim 28 whereinmounting tab regions are isolated by cutting a U-shaped notch in thebase portion to partially separate the mounting tab regions from thebase portion along the notches.
 32. The method of claim 31 wherein thenotches are formed during the separation of the workpiece from thesheet.
 33. The method of claim 18 wherein the mounting portions areformed by welding threaded studs to an upper surface of the baseportion.
 34. The method of claim 18 including bending a forward end ofthe base portion upwardly out of the general plane of the base portion.35. The method of claim 18 including forming tapered regions of therunner portions on forward and rearward ends thereof.
 36. The method ofclaim 18 including forming longitudinally staggered notches in therunner portions and securing carbide wear strips in the notches.
 37. Themethod set forth in claim 18 wherein said separating step comprisesstamp cutting the shaped workpiece from a planar sheet of metal toprovide a flat blank of metal including said central longitudinallyextending base portion and said runner portion side regions on laterallyopposite sides of said base portion.
 38. The method set forth in claim37 wherein said step of stamp cutting includes concurrently stampcutting a notch in a laterally outer edge portion of each of said runnerportion side regions.
 39. The method set forth in claim 38 wherein saidstep of stamp cutting a notch includes the step of longitudinallystaggering the notches on laterally opposite sides of the metal blank.40. The method set forth in claim 39 wherein said bending step isaccomplished by folding said runner portion side regions in oppositedirections out of the plane of said base portion to confrontingpositions.
 41. The method set forth in either of claim 38, 39 or 40including the step of securing a hardened wear strip, having a hardnessgreater than said predetermined hardness of said metal material, in eachof said notches.
 42. The method set forth in claim 37 wherein said stampcutting step includes cutting said runner portion side regions withopposite edges initially lying in the same plane, and include forwardlyconverging forward edge portions and rearward converging rear edgeportions.
 43. The method set forth in claim 42 wherein said step ofcutting includes cutting a notch in said side edges interadjacent saidforwardly converging forward edge portions and said rearwardlyconverging edge portions.
 44. The method set forth in claim 37 whereinsaid step of stamp cutting includes cutting said flat blank of metalsuch that said base portion includes a rear base portion, having apredetermined width, disposed between said runner portion side regionsand a forward edge nose portion having a lesser predetermined widthprojecting forwardly of said runner portion side regions.
 45. The methodset forth in claim 44 further including the step of upwardly bending atleast the terminal end portion of said nose portion relative to saidrear base portion.
 46. A method of fabricating a runner for mounting onthe underside of a snowmobile ski, comprising: stamp cutting a shapedworkpiece from a planar sheet of metal having a predetermined hardness,a generally uniform thickness, and upper and lower faces to provide aflat stamped blank having a longitudinally extending central base andlaterally opposite side edge portions on laterally opposite sides ofsaid base; said stamp cutting step including cutting said laterallyopposite side edge portions with curvilinear forward and rearward edgeportions extending forwardly and rearwardly, respectively, of anintermediate edge portion; said stamp cutting step further includingcutting a notch in each of said intermediate edge portions; and foldingthe laterally edge portion in opposite directions out of the plane ofsaid base to confronting positions on the underside of said base. 47.The method set forth in claim 50 wherein said stamp cutting stepincludes cutting said notches in longitudinally staggered relation toeach other.
 48. The method set forth in claim 46 wherein saidcurvilinear forward edge portions on opposite sides of said baseforwardly converge.
 49. The method set forth in claim 48 wherein saidcurvilinear rearward edge portions on opposite sides of said baserearwardly converge.
 50. The method set forth in claim 46 including thestep of forming mounting portions on said base that projects upwardlyfrom said upper surface of said base.
 51. The method set forth in claim46 wherein said stamp cutting slip includes cutting a U-shaped notch insaid base to partially separate a mounting tab portion from the basealong the notch, and said step of forming mounting portions includesupwardly bending said mounting tab portion out of the plane of the base.52. The method set forth in claim 48 further including the step ofdisposing a hardened wear strip, having a hardness greater than saidpredetermined hardness, into each of said slots and metallurgicallybonding said wear stamp in said slots to said runners.
 53. A runner fora snowmobile ski, comprising: a runner body having a central baseportion and a pair of runner portions fabricated of a single piece ofmetal of a predetermined hardness and bent to a generally U-shapedconfiguration such that the runner portions project transversely of thebase portion and terminate at free edges; hardened wear strips having ahardness greater than said predetermined hardness, secured to said lowerfree edges; and mounting structure formed as one piece with said runnerbody out of said central base portion and operative to secure saidrunner to the ski.
 54. The runner of claim 53 wherein the mountingstructure comprises mounting tab portions bent upwardly from the centralbase portion away from said runner portions
 55. The runner set forth inclaim 54 wherein said mounting tab portions and said base portion are ofequal thickness.
 56. The runner set forth in claim 55 wherein saidmounting tab portions are flat and have screw threads.
 57. (canceled)